Salt is used as a food supplement to enhance the taste of food. Salt is one of the few commodities that are being universally consumed by almost all sections of communities irrespective of socioeconomic status. It is consumed approximately at a level of 5-15 grams/day/person throughout the year. Hence salt is an attractive vehicle to introduce any nutrient supplement (M. G. Venkatesh Mannar, S. Jaipal and C. S. Pandya, Proceedings of Sixth. International Congress, Seoul, 1989). For example, salt is iodized for the control of goiter and it is fortified with iron for control of anemia. Salt is also a good vehicle for supply of other nutrients such as potassium, magnesium and calcium.
Reference may be made to Shuqing Wang in patent no. CN 1271541 A, 1 Nov. 2000, entitled “Multi-element low sodium nutritive salt”, who disclosed the preparation of low sodium nutritive salt by crystallising salt from saturated brine under vacuum. The salt is then mixed uniformly with salts such as KCl and MgSO4.7H2O, followed by mixing with KIO3 and Na2SeO3 solutions, drying and finally mixing with active Ca and Zn lactate. The drawback of this process is that apart from the difficulty of mixing various constituents in a homogeneous solid mixture, salt is to be crystallised from hot saturated brine involving high energy consumption thereby increasing the cost of production. Moreover, such a salt is not natural in its constitution.
Reference may be made to “The Heinz Handbook of Nutrition” by Benjamin T. Burton, published for H. J. Heinz Co., by McGraw Hill Book Co. Second Edition, 1965, page 132-133, which describes the dietary need for potassium.
Reference may be made to R. N. Vohra et al. in pending PCT Patent Application No.PCT/IN02/00018, dated 31 Jan. 2002 entitled “A Process for Recovery of Low sodium Salt from Bittern”, who disclosed the preparation of a mixture of sodium chloride and potassium chloride containing other nutrients such as magnesium and calcium by a natural process from sea/sub-soil bittern. The main drawback of the process is that the salt does not contain any micronutrients.
Reference may be made to Rock Salt, e.g., the brand REAL SALT being sold in the U.S. market, which contains several essential micronutrients such as iron, manganese and iodine but which does not contain appreciable quantities of important essential nutrients such as potassium, calcium, magnesium and zinc. Moreover, Rock salt is available only in very limited regions of the world.
Reference may be made to Charnock, A. [(1989, December). Plants with a taste for salt. New Scientist, 3, pp. 41, 45] and E. P. Glenn, et al, [(1991) Salicornia bigelovii Torr.: An oilseed halophyte for seawater irrigation. Science, 251, 1065-67] who have described cultivation of salt tolerant plants as a potential economic activity utilizing saline wasteland and seawater irrigation. Although it is described in the publications that halophytes such as Salicornia are especially suitable for production of nutritious edible oil with high level of polyunsaturates, deoiled poultry feed, and fodder that is suitable for cattle either as a mixed feed or which can be used alone after desalinating the fodder by washing, no mention is made with regards to recovery of salt from the plant.
Reference may be made to M. P. Reddy, et al, Biol. Plant. 1993, 35, 547-553, who reported that halophytes possess the ability to concentrate salts of sodium, potassium, calcium, magnesium and to some extent micronutrients equaling or exceeding those of sea water in their leaves and stem when grown in saline conditions without adverse effects on growth and biomass production. However no attempt was made to produce salt. No attempt was also made to bias the composition of salts in the plant.
G. Naidoo and R. Rughunanan in J. Exp. Bot., 1990, 41, 497-502, have studied the salt tolerance of Sarcocornia natalensis by irrigating the plants with different concentrations (50 to 300 moles/m3) of NaCl and examining the differences in ion content of the plants. No attempt was made to produce salt.
T. J. Flowers and Y. Yeo in Aust. J. Plant Physiol. 1986, 13, 75-81, have stated that the dicotyledonous halophytes accumulate sodium and chloride ions to an extent of 30-50% by dry weight to maintain osmotic potential at higher salinity level. No attempt was made to produce salt.
Though it was known (T. F. Neals and P. J. Sharkey, Aust. J. Plant Physiol, 1981, 8, 165-179, S. Cherian et al, Indian J. Plant Physiol, 1999, 4, 266-270, S. Cherian and M. P. Reddy, Indian J. Plant Physiol, 2000, 5, 32-37 etc.) that certain halophytes accumulate reasonable amount of sodium, potassium, calcium and magnesium, the main focus of the work was to undertake mechanistic studies and none of the above attempted to produce nutrient rich salt from such plants.